Summary/Abstract This administrative supplement responds to NOT-OD-20-032; Notice of Special Interest: Administrative Supplements for Research on Sexual and Gender Minority (SGM) Populations. Alcohol and other drug (AOD) use is a significant contributor to health and other functional disparities among sexual and gender minorities (SGMs). Some SGM individuals, particularly young adults, are more likely to use AOD compared to non-SGM peers. Prior work has reported on functional disparities across SGM and non-SGM young people, as well as differences in longitudinal patterns of AOD use across these groups. However, few studies have addressed how developmental trajectories of AOD use during adolescence and emerging adulthood may contribute to the emergence of disparities for SGM young adults, especially across multiple domains of functioning (e.g., academic and occupational functioning; social functioning). For example, very little is known regarding whether trajectories of AOD use during these important developmental periods may disproportionately affect outcomes for SGM individuals, or which domains of functioning may be differentially affected in young adulthood. Given that disparities may appear across a variety of different domains, it is crucial to assess AOD- related disparities across multiple domains of functioning to better understand how these negative outcomes may manifest for SGM individuals. Additionally, evidence suggests that subgroups of SGMs may differ with respect to patterns of AOD use, yet little research has addressed the emergence of AOD-related functional disparities within SGMs (e.g., by race/ethnicity). The proposed supplement research will utilize existing longitudinal data from the ongoing STudy of Racial diversity in AOD use during the Transition to Adulthood (STRATA; R01AA025848) to address these gaps. The rich, demographically diverse STRATA dataset will allow us to assess different types of AOD use (alcohol, marijuana, and other drugs) and outcomes across multiple domains with a large longitudinal sample. Study aims are: Aim 1. Examine trajectories of AOD use (i.e., alcohol, marijuana, and other illicit drugs; examined in separate models) over 11 years from early adolescence through young adulthood as predictors of functioning across multiple domains within SGM young adults: 1) risk behaviors (e.g., sexual risk-taking, delinquency), 2) physical health, 3) mental health, 4) social /relationship functioning, 5) academic functioning, and 6) occupational functioning; Aim 2. Determine whether disparities exist by assessing whether trajectories of AOD use are differentially associated with functioning in young adulthood for SGM versus non-SGM peers; and Aim 3. Within SGMs, assess whether AOD use trajectories differentially predict outcomes across racial/ethnic groups (i.e., racial/ethnic disparities within SGM) and sex/gender. Study findings will provide critical information on the emergence of AOD-related disparities for SGMs and can inform prevention and intervention efforts to reduce AOD-related harms.